A pilot study investigating circulating trimethylamine N-oxide and its precursors in dogs with degenerative mitral valve disease with or without congestive heart failure

J Vet Intern Med. 2019 Jan;33(1):46-53. doi: 10.1111/jvim.15347. Epub 2018 Dec 3.

Abstract

Background: Pathophysiologic mechanisms for the development and progression of degenerative mitral valve disease (DMVD) remain elusive. Increased concentrations of circulating trimethylamine N-oxide (TMAO) and its precursors choline and l-carnitine are associated with the presence and severity of heart disease in people.

Objectives: To determine if differences exist in plasma concentrations of TMAO, choline, or l-carnitine among dogs with DMVD and congestive heart failure (CHF), dogs with asymptomatic DMVD, and healthy control dogs.

Animals: Thirty client-owned dogs: 10 dogs with CHF secondary to DMVD, 10 dogs with asymptomatic DMVD, and 10 healthy control dogs.

Methods: A pilot cross-sectional study in which echocardiography was performed and fasting plasma concentrations of TMAO, choline, and l-carnitine (total and fractions) were measured.

Results: TMAO (P = .03), total l-carnitine (P = .03), carnitine esters (P = .05), and carnitine esters to free carnitine ratio (E/F ratio; P = .05) were significantly higher in dogs with CHF compared to those with asymptomatic DMVD. TMAO (P = .02), choline (P = .01), total l-carnitine (P = .01), carnitine esters (P = .02), free carnitine (P = .02), and E/F ratio (P = .009) were significantly higher in dogs with CHF compared to healthy controls.

Conclusions and clinical importance: Dogs with CHF secondary to DMVD had higher concentrations of TMAO compared to both asymptomatic DMVD dogs and healthy controls. Larger prospective studies are warranted to determine if TMAO plays a role in the development or progression of DMVD or CHF.

Keywords: canine; carnitine; choline; congestive heart failure; heart; intestinal; microbiota.

MeSH terms

  • Animals
  • Carnitine / blood*
  • Case-Control Studies
  • Choline / blood*
  • Cross-Sectional Studies
  • Dog Diseases / blood*
  • Dog Diseases / diagnostic imaging
  • Dogs
  • Echocardiography / veterinary
  • Female
  • Heart Failure / blood
  • Heart Failure / complications
  • Heart Failure / diagnostic imaging
  • Heart Failure / veterinary*
  • Male
  • Methylamines / blood*
  • Mitral Valve Insufficiency / blood
  • Mitral Valve Insufficiency / complications
  • Mitral Valve Insufficiency / diagnostic imaging
  • Mitral Valve Insufficiency / veterinary*
  • Pilot Projects

Substances

  • Methylamines
  • trimethyloxamine
  • Choline
  • Carnitine